Interior Minister Chaudhry Nisar Ali Khan made the announcement late on December 21.

The Interior Ministry has cleared these prisoners for execution and their clemency appeals have been rejected by the president, Nisar told reporters in Islamabad.

"The executions must start...within the next couple of weeks," Nisar said.

Nisar also said the decision to lift a moratorium on the death penalty in terrorism-related cases was taken before a devastating militant attack on a school in Peshawar on December 16.

Prime Minister Nawaz Sharif approved an end to the moratorium a day after the attack, in which gunmen killed 132 children and nine staff at a military-run school in the northwestern city. The Pakistani Taliban claimed responsibility.

Pakistan imposed a moratorium on implementing the death penalty in 2008, and rights groups have criticized the decision to lift it.

New York-based Human Rights Watch (HRW) has called on Pakistan to immediately stop the execution of death-row prisoners.

"Pakistan’s government has chosen to indulge in vengeful blood-lust instead of finding and prosecuting those responsible for the horrific Peshawar attack," said Phelim Kine, HRW deputy Asia director.

"The government’s death penalty spree is a craven politicized reaction to the Peshawar killings that will do nothing to bring the attackers to justice," he said on December 20.

Pakistani security officials have secured prisons across the country.

According to the Justice Project Pakistan, a Pakistan-based rights organization, there are around 8,200 people on death row, including around 1,000 convicted of crimes related to terrorism.

​Six people have been executed since the moratorium was lifted.

Four of them were executed on December 21 at a tightly guarded Faisalabad jail after being convicted of involvement in a 2003 attack targeting Pakistan's president at the time, military ruler Pervez Musharraf.

A Punjab provincial official identified one of the men as a Russian national named Akhlaque Ahmed who was also known as Russi.

Two others were executed at the same prison on December 19.

During his briefing, Nisar said the militants who carried out the Peshawar school attack were all Pakistani nationals.

He said several people suspected of plotting the attack have been arrested in recent days.

A Pakistani Taliban spokesman said the group attacked the school in revenge for a military operation in which the army says it has killed more than 1,200 militants in North Waziristan since mid-June.

Nisar said Pakistani troops do not target civilians, including "the families and children of militants."

The interior minister appealed to all citizens, mosques, and other institutions to help authorities fight terrorism.

Nisar called on people to report any suspicious activity to police. He also urged hotels and house owners to thoroughly check potential tenants' backgrounds before renting out their property.

The minister also called on media to refrain from giving coverage to militants, and asked mobile phone sellers to issue SIM cards only after thorough scrutiny.